Rail transportation system and method of designing same

ABSTRACT

A transportation system and a method of designing same, according to which a car travels along a track and is located relative to the track so that the composite center of gravity of the car is offset from the track in a lateral and longitudinal direction.

BACKGROUND

This invention relates to a transportation system, and method of designing same, in which a vehicle travels along a guide way or track.

Public transportation systems, including monorail systems, two-track systems, magnetic levitation systems, etc., are becoming increasingly important as the population of urban areas continues to grow. It is important that these types of systems be economically feasible, yet be stable enough to insure that the vehicles will maintain their stability during all operating conditions. According to most prior designs, a vehicle, or series of interconnected vehicles, move over a track, or guide way, and the design is such that the center of gravity of each vehicle, even when it is loaded with passengers, baggage, etc., and subjected to external dynamic forces, is located within an area defined within the track or guide way to insure that the vehicle maintains adequate stability during all operating conditions. Therefore, in these arrangements, the width of each vehicle, and therefore its capacity, must be kept at relatively low values, which severely restricts the load (i.e., passenger) carrying ability of the vehicle.

Applicant's U.S. Pat. No. 3,985,081 addresses this problem by disclosing a vehicle that is laterally spaced from, and supported by, a guide way on which the tracks are mounted. However, this patent does not disclose any range of possible locations of the center of gravity of the vehicle, including a location in the longitudinal direction, thus limiting the ability to design a vehicle with a relatively large width, and therefore increased capacity.

Therefore, what is needed is a system of the above type that overcomes this defect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a rail transportation system according to an embodiment of the present invention;

FIG. 2 is a side elevation view of the embodiment of FIG. 1;

FIG. 3 is a front elevation view of the embodiment of FIG. 1;

FIGS. 4 and 5 are views, identical to that of FIG. 3, but depicting techniques in designing the embodiment of FIG. 1.

FIG. 6 is a isometric view of the embodiment of FIG. 1 also depicting the design technique for the latter embodiment.

DETAILED DESCRIPTION

Referring to FIGS. 1-3 of the drawings, the reference numeral 10 refers, in general, to a vehicle that moves along a guide way 12 that is supported in an elevated position by a plurality of columns 13, one of which is shown. The vehicle consists of a cabin 14, a housing 16 that extends from the cabin 14 to one side of the guide way 12, and a support arm 18 that extends from the cabin 14 to the other side of the guide way. The housing 16 and the arm 18 support the cabin 14 relative to the guide way in a manner to be described. The housing 16 and the arm 18 can be connected to the cabin 14 in any conventional manner or can be formed integrally with the cabin.

The cabin 14 extends above the guide way 12, and is laterally offset from the guide way 12 to the extent that the vertical axis V (FIG. 3) of the cabin is laterally offset from the guide way 12 in a direction to the left as viewed in FIG. 3, for reasons to be described. The lower surface 12 a of the guide way 12 extends horizontally and is supported on the upper surface of the column 13 in any known manner. The guide way 12 is configured to define two support surfaces 12 b and 12 c (FIG. 3), each of which extends at an angle to the horizontal surface 12 a. The particular angle that each surface 12 b and 12 c extends to the horizontal will be discussed below.

The housing 16 and the arm 18 have outer surfaces 16 a and 18 a, respectively, which extend in a closely spaced, parallel, relation to the surfaces 12 b and 12 c, respectively.

A pair of spaced longitudinally-extending rails, or tracks, 20 a and 20 b are mounted on the surface 12 b in any conventional manner, and are engaged by two corresponding wheels 22 a and 22 b that are rotatably mounted to the housing 16 in any conventional manner. The wheels 22 a and 22 b project from the housing 16, extend perpendicular to the surfaces 16 a and 12 b, with the outer circumferences of the wheels 22 a and 22 b being curved and extending over curved upper surfaces of the tracks 20 a and 20 b. The track 20 b and the wheel 22 b are located relatively close to the vertical axis of the guide way 12, and the track 20 a and wheel 22 a extend outside, i.e., to the left of, the track 20 b and the wheel 22 b.

The wheels 22 a and 22 b are located in the front portion of the housing 16, and it is understood that two additional wheels (partially shown in FIG. 1), identical to the wheels 22 a and 22 b, respectively, are located in the rear portion of the housing in a longitudinally-spaced relation to the wheels 22 a and 22 b.

Preferably, the wheels 22 a and 22 b are driven by an electric motor (not shown) disposed in the housing 16 which would be connected to an electrical power source in a conventional manner. For example, two electrical connectors (not shown) or the like would be mounted to the guide way 12 and to the vehicle 10, respectively. The connecter mounted to the guide way 12 would be connected to a source of electrical power (not shown), and would maintain electrical contact with the other connector when the vehicle 10 moves relative to the guide way 12 to transfer the electrical power to the motor in the housing 16.

The motor drives the wheels 20 a and 20 b in a conventional manner at a speed determined by the speed of the motor, and the wheels propel the car 10 along the tracks 20 a and 20 b in a direction indicated by the arrows in FIGS. 1 and 2. The other set of wheels located in the rear portion of the housing 16 would be powered in the same manner.

The surface 12 c of the guide way 12 is engaged by two wheels 24 a and 24 b that are rotatably mounted to the distal end portion of the arm 18 in any conventional manner. The wheels 24 a and 24 b extend perpendicular to the surfaces 18 a and 12 b, are not powered, and act as a counterbalance in a manner to be described. It is understood that two additional wheels (one of which is shown in FIG. 1), identical to the wheels 24 a and 24 b, respectively, are located in the rear portion of the housing in a longitudinally-spaced relation to the wheels 24 a and 24 b.

Referring to FIG. 3, the center of gravity of the car 10 is laterally offset from the outer track 20 a and the outer wheel 22 a, and from the inner track 20 b and the inner wheel 22 b, in the same direction, i.e., to the left as viewed in the drawing. The specific location of the center of gravity is determined in accordance with the following steps:

-   -   The general desired dimensions of the car 10 and the guide way         12, are determined;     -   The weight of the cabin 14 is determined, taking into         consideration the average amount of people carried by the cabin         and all subsystems contained therein such as the wheels, motor,         transmission, batteries, air conditioning equipment, etc;     -   The individual weights of all components associated with the         cabin 14, such as the housing 16 and the arm 18, are determined,         taking into consideration all subsystems contained therein;     -   The individual centers of gravity of the cabin 14, the housing         16 and the arm 18 are then determined based on their approximate         dimensions and weights, as determined above;     -   Based on the above individual centers of gravity, a composite         center of gravity for the entire car 10 is established in a         conventional manner;     -   The general desired lateral location of the car 10 relative to         the guide way 12 and, more particularly, to the outer track 20 a         and the outer wheel 22 a is determined so that the CG is         laterally offset from the latter wheel (i.e., to the left of the         wheel as viewed in FIG. 2); and     -   The dimensions of the housing 16 and the arm 18, as well as the         location of the wheels 22 a and 22 b on the housing and the         location of the wheels 24 a and 24 b on the arm, are determined         so that the wheels 22 a and 22 b engage the tracks 20 a and 20         b, respectively, and so that the wheels 24 a and 24 b engage the         surface 12 c of the guide way 12.

An example of a location of the composite center of gravity in two planes (corresponding to the width and height of the car) is referred to in FIG. 3 by the reference letters CG. It is noted that, in accordance with the above, the design, dimensions, shape and weight of the car 10, the cabin 14, and the housing 16, and the location of the above subsystems, are selected so that this CG location is laterally offset (to the left as viewed in FIG. 4) of the outer track 20 a and the outer wheel 22 a.

It is understood that the specific location of the CG in FIG. 3 is for the purpose of example only and will vary with each application, but in all cases it will be laterally offset from the track 20 a and the wheel 22 a.

The example of the possible location of the CG shown in FIG. 3 is relative to the width and height of the car 10, and its location in a longitudinal direction, i.e., along the length of the cabin 14, would also be determined in the same manner, based on the mass distribution of the car 10 and its contents in the longitudinal direction. This establishes a longitudinal offset of the CG from the location of the outer track 20 a and the outer wheel 22 a.

The lateral and longitudinal offsets of the CG from the outer track 20 a and the outer wheel 22 a establishes downwardly-directed forces that are equal to the weight at the CG times the distance (moment arm) of the lateral offset and the distance of the above longitudinal offset. These forces considerably add to the stability of the cabin 14 as it moves along the tracks 20 a and 20 b. The range of permissible locations of the CG are determined in a manner to be described.

As stated above, an additional set of wheels are located in the rear portion of the housing 16 that are identical to the wheels 22 a and 22 b and are longitudinally spaced rearwardly from the latter wheels. It can be appreciated that the above location of the CG for the wheels 22 a and 22 b would also be applicable to the wheels located in the rear portion of the housing. Similarly, an additional set of wheels (not shown) are located in the rear portion of the arm 18 which are identical to the wheels 24 a and 24 b and are longitudinally spaced rearwardly from the latter wheels.

The angles that the surfaces 12 b and 12 c extend to a horizontal plane are established as follows:

-   -   (1) It will be assumed that the cabin 14 is positioned relative         to the guide way 12 as shown in FIG. 3 as a result of         establishing the laterally offset CG discussed above. In this         position the vertical axis V of the cabin is laterally offset,         i.e., extending laterally outside (or to the left as viewed in         FIG. 4), from the guide way 12. The wheels 22 a and 22 b of the         housing 16 and the wheels 24 a and 24 b of the arm 18 are         slightly spaced from the surfaces 12 b and 12 c, respectively,         although the angles of these surfaces have not yet been         determined.     -   (2) A position point, P1, is established that is laterally         offset from the wheel 22 a, as viewed in FIG. 4, and is located         on the left side of the cabin 14, and between the top and the         bottom of the cabin. According to the example shown in FIG. 4,         the point P1 extends from the left side of the cabin 14 for a         distance corresponding to approximately one-third the width of         the cabin, and approximately mid-way between the top (roof) and         bottom (floor) of the cabin. Although the point P1 will always         be laterally offset from the wheel 22 a (i.e., to the left of         the wheel), and above the bottom, or floor of the cabin 14, as         viewed in FIG. 4, its precise location is not critical and can         be based on empirical data established by prior design efforts.     -   (3) From the point P1, an arc (circle) is drawn to and through a         point P2 at the general location of the outer wheel 22 a, which,         for the purpose of this example, is at the side wall of the         wheel 22 a along the diameter of the wheel. The location of         point P2 is approximate, since the angle of the surfaces 12 b         and 16 a, and therefore the angle of the wheels 22 a and 22 b,         have not yet been determined.     -   (4) The points P1 and P2 are connected by a line L1 and a line         perpendicular to the line L1 is drawn through the point P2.         Although this line is not shown in FIG. 4, it coincides with the         surface 16 a. Since, as set forth above, the surface 12 b is         parallel to the surface 16 a, the angle of the line coinciding         with the surface 16 a also establishes the angle that the         surface 12 a of the guide way 12 extends to the horizontal.     -   (5) The wheel 22 a is mounted in the housing 16 proximate to         point P1, extending perpendicular to the surface 12 b, and in         engagement with the track 20 a.     -   (6) The inner wheel 22 b is then mounted on the housing 16 and         is spaced from the wheel 22 b a distance corresponding to the         distance between the tracks 20 a and 20 b. The wheel extends         perpendicularly to the surface 12 b and in engagement with the         track 20 b.     -   (7) The same procedure discussed above is used to establish the         angle that the surface 18 a, and therefore the surface 12 c,         make with the horizontal. This procedure involves line L2 and P3         that are used in the same manner as L1 and P2, respectively, and         therefore it will not be described in detail.     -   (8) The wheel 24 b is mounted in the arm 18 proximate to the         point P3 and so that it extends perpendicular to the surfaces 12         c and engages the latter surface. The wheel 24 a is then mounted         on the arm 18 in a spaced relation to the wheel 24 b and so that         it extends perpendicularly to the surface 12 a and engages the         latter surface 12 c.

Once the angles of the surfaces 12 b and 12 c, and therefore the location of the wheels 22 a, 22 b, 24 a and 24 b are established in accordance with the foregoing, then a permissible range of locations of the CG in both the lateral and longitudinal directions that will insure that the cabin 14 will maintain its stability during all operating conditions is determined in accordance with the following.

Referring to FIG. 5, the two lines, line L1 and L2, and the points P1 and P2 are used in the determination of the range of locations of the CG. Also, an additional imaginary line L3 is extended from the outside (i.e., to the right as viewed in FIG. 5) of the wheel 22 b, and perpendicular to, the surfaces 12 b. An additional imaginary line L4 is extended from the inside (i.e., to the left as viewed in FIG. 5) of the wheel 24 a, and perpendicular to, the surfaces 12 c. The lines L3 and L4 are extended until they intersect at point P4.

A horizontal line L5 is then extended from point P4 that intersects line L1 at point P5, and a vertical line L6 is extended from point P4 that intersects line L2 at point P6. The lines L5, L6, the portion of the line L1 extending between the points P1 and P5, and the portion of the line L2 extending between the points P1 and P6, establish an envelope of the lateral and vertical limits (in the plane of the drawing) for the location of the CG.

The above procedure is repeated in connection with the rear wheels (that are identical to the front wheels 22 a, 22 b, 24 a, and 24 b in order to extend the above envelope in the longitudinal direction of the cabin 14. In particular, the points P1′, P4′, P5′, and P6′, as well as the lines L1′, L2′, L5′, and L6′ are initially established in connection with the rear wheels in the same manner as discussed above in connection with the points P1, P4, P5, and P6, and the lines L1, L2, L5, and L6, respectively, in connection with front wheels 22 a, 22 b, 24 a, and 24 b. This establishes an envelope for the rear wheels consisting of the interconnected lines L5′, L6′, the portion of the line L1′ extending between the points P1′ and P5′, and the portion of the line L2′ extending between the points P1′ and P6′. This latter envelope is identical to the same envelope established above in connection with the front wheels 22 a, 22 b, 24 a, and 24 b.

Then the points P1 and P1′ are connected, the points P4 and P4′ are connected, the points P5 and P5′ are connected, and the points P6 and P6′ are connected to extend the above envelope in a third dimension coinciding with the longitudinal direction of the cabin 14.

Thus, if the location of the CG is within the above three dimensional envelope, it will be insured that the car 10 will maintain stability during all operating conditions, due to the location of the stabilizing forces created by the weight of the car at the offset CG and the above-mentioned moment arms, or distances between the CG and the outside front wheel 22 a and the outside real wheel, as discussed above. An example of a location of the CG in the longitudinal direction is shown in FIG. 6.

It is understood that the dynamic loading on the cabin 14 also continuously varies when the vehicle is in use. For example, the tracks 22 a and 22 b will include straight portions and curved portions, and when the cabin 14 moves from a straight track portion to a curved track portion and vice versa, the dynamic loading on the vehicle will vary accordingly. Also, the dynamic loading on the cabin 14 will vary with variations in the wind conditions acting on the vehicle, etc. However, the stabilizing forces discussed above will maintain the stability of the cabin 14 as long as the CG stays within the above envelope, or range of locations. It is understood that additional vehicles, identical to the cabin 14, can be connected together and to the cabin 14 in a conventional manner and that each additional vehicle would be designed in the same manner described above in connection with the cabin 14.

Several advantages result from the above and examples are as follows:

-   -   Since the preferred embodiment utilizes an electric motor, the         energy saving realized by transporting a high volume of people,         which otherwise could be using automobiles powered by internal         combustion engines, is significant.     -   The wheels 20 a and 20 b, as well as the wheels 24 a and 24 b,         extend perpendicular to the angled surfaces 12 b and 12 c which         insures continuous contact and traction between the wheels and         the track, while reducing the tendency for the cabin 14 to         oscillate about its points of contact with the tracks 20 a and         20 b.     -   The increased stability of the car 10 as it moves along the         tracks 20 a and 20 b, as discussed above, enables a relatively         wide cabin 14 to be utilized that holds a relatively large         number of people.     -   The guide way 12, the supports 13, and the car(s) 10 can be         easily elevated above the ground in the same right-of-way areas         used by existing transportation systems, thus eliminating, or at         least substantially reducing, the need for acquisition of new         land space for the construction of the system.

Several variations of the above embodiments may be made within the scope of the invention and examples are set forth below.

-   -   Other modes of power may be used to propel the drive wheels 22 a         and 22 b, such as internal combustion or turbine engines.     -   Power may be supplied to the wheels 24 a and 24 b.     -   The specific shape of the cabin 14 can be varied.     -   The locations of points P1 and P1′, above, are for the purpose         of example only, it being understood that they vary as long as         they are laterally and longitudinally offset from the wheel 22         a, or from an area proximate to the wheel, and are elevated from         the bottom (floor) of the cabin 14.     -   The specific design of the guide way 12 can be varied as long as         the angled surfaces 12 b and 12 c are provided.     -   The number of wheels engaging the guide way 12 can be varied.     -   The types of wheels 22 a, 22 b, 24 a, and 24 b, and their         engagement with the tracks 20 a and 20 b and the surface 12 c         can be varied.

Those skilled in the art will readily appreciate that many other variations and modifications of the embodiment described above may be made without materially departing from the novel teachings and advantages of this invention. Accordingly, all such variations and modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. 

1. A method of designing a transportation system including a car that travels along at least one track; the method comprising; determining the composite center of gravity for the car; and locating the car relative to the track so that the composite center of gravity is offset from the track in a lateral and longitudinal direction.
 2. The method of claim 1 wherein the step of determining the composite center of gravity comprises: determining the approximate desired dimensions of the car; determining the approximate weight of the car; determining the approximate weights of all components and subsystems associated with the car; establishing individual centers of gravity of the car and components based on their approximate dimensions and weight; establishing the composite center of gravity for the car, including the components and the subsystems based on their individual centers of gravity.
 3. The method of claim 1 wherein the lateral offsets of the composite center of gravity from the track establishes downwardly-directed forces that are equal to the weight at the center of gravity times the distance of the above lateral offset and the distance of the above longitudinal offset.
 4. The method of claim 1 wherein the components are a housing for receiving at least one wheel that engages the track and an arm for receiving at least one wheel that engages the track.
 5. The method claim 1 wherein the track is mounted on a surface on the guide way, and the at least one wheel is mounted on the car and engages the track, and further comprising establishing an angle that the surface makes with a horizontal plane.
 6. The method of claim 5 wherein the step of establishing the angle comprises: establishing a position point that is laterally offset from the wheel and within the boundaries of the car; and connecting a line from the position point to the wheel or proximate to the wheel, wherein the angle of the surface is perpendicular to the wheel and located proximate to the wheel.
 7. The method of claim 1 further comprising providing another surface on the guide way for receiving another wheel and further comprising establishing an angle that the surface makes with a horizontal plane.
 8. The method of claim 7 wherein the step of establishing the angle comprises: establishing a position point that is laterally offset from the other wheel within the boundaries of the car; and connecting a line from the position point to the other wheel or proximate to the wheel, wherein the angle of the other surface is perpendicular to the other wheel and located proximate to the other wheel.
 9. The method of claim 8 wherein the other wheel acts as a counterbalance to the first-mentioned wheel.
 10. The method of claim 1 wherein there are two spaced tracks and two spaced wheels that engage the respective tracks, and wherein the lateral offset of the composite center of gravity is offset from both wheels and both tracks in the same direction.
 11. A transportation system comprising: a guide way defining at least one surface; at least one track mounted on the surface; a car comprising a cabin for receiving passengers and adapted to engage the track and travel over the track; the vertical axis of the car being laterally offset from the guide way; and the center of gravity of the car being laterally and longitudinally offset from the track.
 12. The system of claim 11 further comprising a at least one wheel rotatably mounted on the car and adapted to engage the track.
 13. The system of claim 12 wherein there are two spaced tracks mounted on the surface and two spaced wheels rotatably mounted to the cabin and engaging the corresponding tracks.
 14. The system of claim 11 wherein the lateral offset of the composite center of gravity is offset from both wheels and both tracks in the same direction.
 15. The system of claim 11 wherein the lateral offsets of the center of gravity from the wheel establishes downwardly-directed forces that are equal to the weight of the car at the center of gravity times the distance of the above lateral offset and the distance of the above longitudinal offset.
 16. The system of claim 11 wherein the surface extends at an angle to the horizontal.
 17. The system of claim 16 wherein the guide way defines another surface extending at an angle to the horizontal, and wherein the car further comprises an arm, and at least one wheel mounted on the arm and engaging the other surface.
 18. The system of claim 17 wherein the at least one other wheel acts as a counterbalance to the first-mentioned wheel. 